Railway-traffic-controlling apparatus



1927. 7 May 24, L. o. GRONDAHL RAILWAY TRAFFIC CONTROLLING APPARATUS Filed June 11, 1924 lwy lx ATTORNEY Patented May 24, 1927.

UNITED STATES LABS 0. .GRONDAHL,

or rir'rs 1,629,617 PATENT OFFICE.

BURG I-I, PENNSYLVANIA ASSIGNOR TO TI-IE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY-TRAFFIC-CONTROLLING APPARATUS.

Application filed June 11, 1924. Serial No. 719,332.

My invention relates to railway traific controlling apparatus,

and particularly to apparatus of the type comprising train carried governing mechanism controlled by energy recevied from the trackway.

T will describe oneform and arrangement embodying of traflic controlling apparatus my invention and will then point out novel features thereof in claims the ' The accompanying drawing is a diagrammatic view showing one form and arrangement of railway traflic controlling apparatus embodying my invention.

Referring to this drawing, the reference characters 1 and 1 designate th of a' stretch of railway track e track rails over which trailic normally moves the direction of the arrow. is. divided from means of insulated stood that any desired number A section A B 1 of this track the rest of the stretch by joints 2, it being under- I or such sections may be placed end to end to form a complete system.

Alternating train controlling current is at times supplied to the rails of the section .by a transformer J having a secondary winding 3 constantly connect-ed acrossthe rails adjacent the exit end The primary 4 of this times supplied with alternating from some suitable source such the section.

transformer J is at current as an alternator M. The supply of current to primary 4 may be controlled by strmneiitality and fro] is accomplished any by means 0 suitable inas here shown this conf front contact 5 of a traclcrelay R associatedwith the section in advance of point n. It will be obviousthat when relay R is energized,

section A-B issupplied with ing train controlling current which in opposite directions 1n the two track at any instant.

Carried on the tram 1n an alternatflows rai ls some convenient location such as in advance of the forward axle'of the locomotive are two windings 6 and 6 in inductive relation with the track rails 1 and 1 respectively. windings 6 and vibration relays C and These two pp y gy to two D, respectively.

Referring Jarticularl to rela C this relay comprises a core 10 prov coil 7, and a polarized left handend'of armature 11 is tened to the left hand end of ided with a armature 11. The

rigidly fasthe core 10,

air gap.

the other end being free to vibrate. Coil 7 is connected in series with winding 6 and the circuit is tunedto resonance at the frequency of the current in the track rails by means of a series condenser 8. The armature 11 is tuned to mechanical resonance at the frequency of the current in the track rails by suitably loading the free end with a weight 12 which also serves as a contact, as explained hereinafter. lay D is similar to relay G and will be understood without further explanation. Coil 7 of relay D is connected with winding 6 and the circuit is tuned to. reso-h nance at the frequency of the current in the track rails by a condenser 8 The two relays C and D are so disposed that the free ends of the two armatures of these relays are adjacent each other, but the parts'are so proportioned that when relays C and D are ole-energized the weights12, 12 of the two armatures are separated by a small If,- however, the train occupies a stretch of track which is induced in winding (Scauses armature 11 of relay C to vibrate at the frequency of the train controllingcurrent, and similarly the voltage induced in winding 6 causes armature 11 of relay D to vibrate at this same frequency. The parts are so proportioned and disposed that for train controlling current which flows in opposite directions in the two track rails at an instant the armature of relay C is drawn downwardly at.

pulsating direct current of the same frequency. Primary 15 of transformer T is tuned to approximate resonance at the frequency of the current supplied thereto by means of a condenser 14 shunted across this H being supplied "With train cont-rolling current the Voltage primary. Train governing mechanism of any suitable form and here illustrated as a relay H, is controlled by secondary l6 throughthe medium of a rectifier G. V

will be clear that when the track is supplied with train controlling current, re lays C and I) are operated to vibrate t he associated arinatures, and since the 'relays are so connected that the" armatures are attracted simultaneously and repelled simut taneously, contact l212 is in'tern'iittently closed. The pulsating direct current thus supplied to transformer T causes an alternating current to be induced in secondary l6, and this alternating current, rectified by rectifier (l, energizes relay H.

One advantage of my invention is that false operation can not be obtained as the result of stray alternating current liowing through the two rails in parallel. In the event of a stray current flowing in this manas before but each armature v.-'ould then be attracted while the other is being repelled, and so contact 12-l2 would not be closed.

Another advantage of my invention is that alternating current in one rail only would nor, the relays C and I) would be energized energize only one relay and hence contact,

1212 would remain open.

Although I have herein shown and described only one form and arrangement of railway traliic controlling apparatus embodying my invention, it is underst-oodthat various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track, means for at times supplying to said stretch an alternating current which flows in opposite directions in the two track rails at an instant, two train carried windings in inductive relation with the twotrack rails res ectively, two vibration relays receiving energy from said two windings respectively, and train governing mechanism controlled jointly by said relays.

2. In combination, astretch of railway track, means for at times supplying to said stretch an alternating currentwhich flows in opposite directions in the two track fails at an instant, two train carried windings in inductive relation with the two track rails respectively, two vibration relays each comprising an armature tuned to mechanical resonance at the frequency of said alternat ing current and said relays receiving energy from said two windings respectively, and

tram governing mechanism controlled jointlyby said relays.

3. In combination, a stretch of railway track, means for at times supplying to said stretch an alternating current which flows in opposite directions in the two track rails at an instant, two train carried windings in inductive relation with the two track rails respectively, two vibrationre'lays receiving energy from said two windings respectively, and each comprising an armature which armatures are normally spaced apart but are arranged to be swung periodically into contact when said stretch is supplied with such alternating current, and train governing mechanism controlled by said armatures.

l. In combination, a stretch of railway track, two windings in inductive relation with the two rails otthe stretch respectively, two vibration relays receiving energy from said two windings, respectively, and

each comprising a vibratable armature havlug a stop associated therewith to limit the motion of such armature toward the remaining armature, means for at times supplying an alternating current to the rails oi the' stretchin series to swing saio armatures into intermittent contact, and train governing mechanism controlled jointly by said armatu'resi g, V

5. In combination, a stretch of railway track, means for at times supplying to said stretch an alternating .current which flows in opposite directions in the twotrack rails at an instant, twoftra in carried windings in inductive relation with the two track rails respectively, a first vibration relay in cluded in a circuit containingone of said windings and tuned to approximate resonance at the frequency of said current and comprising an armature tuned'to mechan ical resonance at the frequency of said current, a second vibration relay included in a circuit containing the remaining said winding and tuned to approximate resonance at the frequency of said current and comprising a second armature tuned to mechanical resonance at the frequency or said current, the

relays being so connected with said windings that the armatures are both attracted at the same time and both repelled at the same time and the armatures being so located and proportioned that they. engage once. during each cycle of said current, and train governing mechanism controlled jointly by said armatures. V

6. In combination, a stretch of railway track, means for at times supplying alternating current to the rails of the stretch,

two train carried windings in inductive relation with the two track rails respectively, two vibration relays receiving energy from said two windings respectively, and train governing mechanism controlled jointly by said two relays. I

7. In combination, arailway, a source of alternating current connected across the track rails thereof, two train carried windings in inductive relation with said two track rails respectively, two relays receiving and each including an armature tuned to mechanical resonance at the frequency of said alternating current, train governing mechanism, and means for energizing said mechanism when both of said relays are energized but not when either relay alone is energized.

8. In combination, a railway, a source of alternating current connected across the track rails thereof, two train carried windings in inductive relation with said two track rails respectively, two relays receiving energy from said two windings respectively, and each including an armature tuned to mechanical. resonance at thefrequency of said alternating current, a Contact controlled by said relays and closed when both relays are energized but not when either relay alone is energized, and train governing mechanism controlled by said contact.

9. In combination, a railway, a source of alternating current connected across the track rails thereof, two train carried windings in inductive relation with said two track rails respectively, two relays receiving energy from said two windings respectively, and each including an armature tuned to mechanical resonance at the frequency of said alternating current, and train governing mechanism responding to energization of both of said relays but not to energization of either relay alone.

10. In combination, a railway, a source of alternating current connected across the track rails thereof, two train carried-windings in inductive relation with said two track rails respectively, two relays receiving energy from said two windings respectively, and each including an armature tuned to mechanical resonance at the frequency of said alternating current, and train governing mechanism responding to energization of said relays due to an alternating current flowing through said two rails in series but not to energization of said relays due to an alternating current flowing through said two rails in multiple.

11. In combination, a railway, a source of alternating current connected across the track rails thereof, two train carried windings in inductive relation with said two track rails respectively, two relays receiving energy from said two windings respectively, and each including an armature tuned to mechanical resonance at the frequency of said alternating current, a contact controlled by said relays and closed when both relays are energized due to an alternating current flowing through said two rails in series but not when both relays are energized, due to an alternating current flowing through the two rails in multiple, and train governing mechanism controlled by said Contact.

In testimony whereof I affix my signature.

LARS o. GRONDAHL. 

